Question

已知m+n=-3,mn=2,求-3（1/3n-mn）+2（mn-1/2m）的值

Answer 1

-3(1/3n-mn)+2(mn-1/2m)

=-n+3mn+2mn-m

=-m+(-n)+(2mn+3mn)

=-(m+n)+5mn

再加入那几个的量，就是

-（m+n)+5mn

=-(-3)+5*2

=3+10

=13

答：值是13.